The present invention relates to a semiconductor device and a stacked semiconductor device suitable for use in a three-dimensional mounting technology, methods of manufacturing them, and a circuit board and an electronic instrument including these semiconductor devices.
In order to reduce the size and weight of a portable electronic instrument such as a portable telephone, notebook-type personal computer, or personal data assistant (PDA), electronic parts provided in the electronic instrument, such as a semiconductor chip, have been reduced in size. Moreover, space for mounting the electronic parts is extremely limited. Therefore, the packaging method for the semiconductor chip has been developed, and an extremely small package called a chip scale package (CSP) has been proposed.
Since the mounting area necessary for the semiconductor chip manufactured by using the CSP technology is approximately the same as the area of the semiconductor chip, high-density mounting can be achieved.
However, since the above electronic instrument is expected to be further reduced in size and increased in function, it is necessary to further increase the mounting density of the semiconductor chip.
In view of the above situation, a three-dimensional mounting technology as disclosed in Japanese Patent Application Laid-open No. 2002-50738 has been proposed. This three-dimensional mounting technology increases the mounting density by stacking semiconductor chips having the same function, or by stacking semiconductor chips having different functions, and interconnecting the semiconductor chips.
A semiconductor chip used in the three-dimensional mounting technology includes a connection terminal penetrating the substrate. The chips are electrically connected by stacking the chips through the connection terminals. Conventionally, such a connection terminal is generally processed in a post-processing step after completing the wafer process (from the multilayer interconnection step to the passivation film formation step). This method can be widely used since various devices can be additionally processed. However, such an additional step increases cost.